This "OMG! J. Tweet hates OD&D/us!" topic has been done to death, so I'm just going to hit a couple of brief bullet points, aimed particularly at Tweet's list of "bad stuff" from earlier iterations of D&D. Here's the relevant Tweet quote:

For the record, the "bad stuff" I'm referring to is stuff like: too much arithmetic (5 % XP bonus, copper pieces, etc.), wonky XP progression per class, too-random character creation, and poor class balance. It also has the problem that didn't get fixed until 4e: all spells are daily, which makes spellcasters play too differently from the fighters.

Let's take a closer look at these in turn.

1) Too much arithmetic: 5% XP bonus

I continue to be amazed that people with ordinary educations can't do 5% in their head. Can you halve a number in your head? Can you move the decimal point to figure one tenth of a number? Do both of those operations in whichever order suits you. Ta-da. I'm no math wizard and I can do it.

But let's recognize that not everyone wants to deal with that hassle, so when I run games that use XP bonuses for stats I usually announce XP awards like this "That's 220xp each, 242 if you get a 10% bonus and 231 if you get 5%" Compared to tallying XP for multiple awards and dividing by multiple characters and henchmen (who I count as half a PC each), the 5% bonus is one of the easier steps for me.

On the other hand, we need to admit that the XP bonus system is a vestigal mechanic from pre-Supplement OD&D. In the original game the only mechanical goodie you got from a high Strength, Intelligence or Wisdom was the XP bonus you got if the high stat matched up with your class prerequisite. Once you add in the bonuses from Supplement I: Greyhawk, the XP rules become a form of double dipping. A fighter with a high Str gets both more XP earned and more successes in combat (which equals more XP earned). So while I think the XP bonus system works just fine for pre-Supp OD&D and its retroclone, Swords & Wizardry Whitebox, I also think it's an unnecessary redundancy for most later iterations of the game. So from my point of view Tweet is right about this rule for the wrong reasons.

2) Too much arithmetic: Copper Pieces

I'm not entirely sure what the complaint is here. Nothing in the game requires any PC to collect or use copper pieces. I've known plenty of players who simply round up to the nearest 1 sp. I know a few who only work with gold pieces and better currency. And nothing requires the DM to use cp.

However, that doesn't mean that copper pieces should be cut from the game. In the world of dungeons as logistical challenge, a big pile of copper pieces is basically the DM handing you a length of rope to hang yourself with. It's a variation of the classic "Throne Cut from a Single Ruby" or "6' Tall Solid Gold Statue". Yeah, the treasure is worth a lot, but is it really worth dragging it up six dungeon levels and across 100 miles of wilderness? The DM is hoping you are stupid enough to answer 'yes'.

3) Wonky XP progression per class

I will readily admit that the XP charts are wonky as hell. But the 'improvement' to a unified XP chart supported in Tweet's version of D&D (as well as MERP, Rolemaster, and the new HackMaster Basic) has two basic problems: it demands that the designer meticulously balance all the classes so that a level 7 piglicker is functionally equivalent to a level 7 cogpolisher. And that's assuming the designer knows exactly how the players are going to use the classes. The other problem is that unified XP charts are dull as dirt.

4) Too-random character generation

Someone will have to explain to me where the line between "random" and "too random" is, because I'd totally be down with a set of rules that randomly assigned my class, race, alignment, spells and starting equipment. I'd then gladly start in a random hex of the campaign world.

5) Poor class balance

Complaining about both Wonky XP Progressions and Poor Class Balance is hardly playing fair. If you've done your wonky XP homework then class balance isn't really an issue. And exactly why are we so concerned with balancing classes anyway? Should a wizard level X be balanced against a fighter level X, and if so why did Tweet write Ars Magica, where wizards clearly aren't balanced against anyone else in the party?

Random chargen enters into this issue as well. If you roll dice to determine your stats and a character needs a 17 Charisma to be a Paladin, what does it matter if the class is better than the fighter with its 9 Str minimum? I'd go so far as to argue that the player of the Paladin would be getting the short end of the stick if their PC wasn't clearly cooler than the fighters in the party.

6) All spells are daily

The funny thing is that I totally agree with Tweet on this one, but I totally disagree with the 4e solution. Spells shouldn't be faster, they need to be slower. Give me weekly, monthly, annual and once-in-a-lifetime spells of real ultimate power, please!

7) spellcasters play too differently from the fighters

I continue to maintain that this line of thinking is pure crazy talk. I've known players who enjoyed wizards as written. And I've known players who steer clear of wizards and enjoy the straightforward mechanics of fighterdom. Forcing fighters and wizards to use the same mechanics strikes me as a surefire way to dis-serve at least one of those groups, possibly both. When I get run a PC sometimes I want to play a sword-swinging maniac and sometimes I want to play a wizard with world-bending invocations. I just don't understand how it helps me to reduce those two nifty experiences into one.

"Man, is there anything Jeff CAN'T do when it comes to gaming? This guy is like a critical 20 every roll. Jeff can bite the heads offa five game geeks, including their sorry-ass DM, and spit 'em into a large duffel bag ONE AT A TIME!...that's just the kind of messed up bastard he is! You think yer a gamer, punk? Well..do ya? Jeff will depants your weasel-ass right in front of your grandma."